The Purple Ribbon

In Hyzyd’s school, there are 13 section for K-1 with an average of 38 students per class. On their first day of class, they already wore their uniform plus a purple ribbon (as shown below) to serve as each student’s gps tracking device. You see, on the first day, the teacher adviser doesn’t memorize yet her students. Whenever one or two students lost their way while they went to toilet or playground , the teacher can track her students among the crowd by simply looking on the child’s ribbon color on their uniform. Ain’t it smart way?